전기분해의 화학량론. 2.00 g of zinc 0.0100 amperes

전기분해의 화학량론. 2.00 g of zinc 0.0100 amperes

 

 

The chemical reaction taking place in a dry cell may be written

Zn(s) + 2H^+(aq) + 2MnO2(s) → Zn^2+(aq) + 2MnO(OH)

 

The battery is to be discarded after 2.00 g of zinc is converted to Zn^2+(aq).

If 0.0100 amperes of current is continuously drawn,

for how many seconds can the battery operate?

 

a) [(65.4) (0.0100)] ÷ [(2) (96,500)]

b) [(2) (96,500)] ÷ [(0.0100) (65.4)]

c) [(2) (65.4) (96,500)] ÷ (0.0100)

d) [(2.00) (2) (96,500)] ÷ [(65.4) (0.0100)]

 

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답: d)

 

 

Zn의 몰질량 = 65.4 g/mol

 

 

전하량(C), Q = It

 

 

 

(전하량) (Faraday 상수) (이동한 전자의 몰수) (물질의 몰질량) = 물질의 질량

( 설명 http://ywpop.tistory.com/4461 )

 

(0.0100 A×? sec) (전자 1 mol/96500 C) (Zn 1 mol/전자 2 mol) (Zn 65.4 g/Zn 1 mol) = Zn 2.00 g

 

? = [(2.00)(96500)(2)] ÷ [(0.0100)(65.4)]

= 5.90×10^5 sec